ARM: tegra: pm: add platform suspend support

Adding suspend to RAM support for Tegra platform. There are three suspend
mode for Tegra. The difference were below.

* LP2: CPU voltage off
* LP1: CPU voltage off, DRAM in self-refresh
* LP0: CPU + Core voltage off, DRAM in self-refresh

After this patch, the LP2 suspend mode will be supported.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
diff --git a/arch/arm/mach-tegra/pm.h b/arch/arm/mach-tegra/pm.h
index 787335c..73a45f1 100644
--- a/arch/arm/mach-tegra/pm.h
+++ b/arch/arm/mach-tegra/pm.h
@@ -21,6 +21,8 @@
 #ifndef _MACH_TEGRA_PM_H_
 #define _MACH_TEGRA_PM_H_
 
+#include "pmc.h"
+
 extern unsigned long l2x0_saved_regs_addr;
 
 void save_cpu_arch_register(void);
@@ -32,4 +34,17 @@
 void tegra_idle_lp2_last(u32 cpu_on_time, u32 cpu_off_time);
 extern void (*tegra_tear_down_cpu)(void);
 
+#ifdef CONFIG_PM_SLEEP
+enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
+				enum tegra_suspend_mode mode);
+void tegra_init_suspend(void);
+#else
+enum tegra_suspend_mode tegra_pm_validate_suspend_mode(
+				enum tegra_suspend_mode mode)
+{
+	return TEGRA_SUSPEND_NONE;
+}
+static inline void tegra_init_suspend(void) {}
+#endif
+
 #endif /* _MACH_TEGRA_PM_H_ */